The present invention generally relates to equipment for the floor-care industry, particularly to automatic floor scrubbers, and specifically to automatic floor scrubbers including unique provisions for dampening the vibrations caused by the machine moving over a rough surface and/or provisions for reducing the sound level generated during operation.
An automatic floor scrubber is a commonly used piece of equipment in the floor-care industry. The machine is generally comprised of a tank to hold cleaning solution, a scrub system to agitate the solution on the floor surface in order to loosen dirt, a vacuum squeegee system to pick up the dirty solution, and a tank to contain the dirty solution. The larger automatic floor scrubbers are usually battery powered, and, because the batteries weigh a substantial amount, are equipped with a traction drive system to propel the machine across the floor.
In use, the automatic floor scrubber is used to scrub aisles, hallways, and the like, and to scrub close to objects. Therefore, the automatic floor scrubber is used on a variety of floors, such as smooth tile or concrete, ceramic tile, or rough concrete, so it is advantageous both from the standpoint of operator and machine to provide a means of dampening the vibrations caused by the machine moving over a rough surface. Current means for providing dampening in automatic floor scrubbers has been utilizing cushion tires. However, cushion tires have a lower load rating than a noncushion tire for a given size, so the tire size must be substantially increased. This necessitates a less compact machine, causing potential maneuvering difficulties. Alternately, spring caster wheels, which provide a degree of suspension, have been utilized for dampening in automatic floor scrubbers. These spring casters, however, are very expensive, and in many cases are not economically feasible.
Additionally, automatic floor scrubbers are often utilized in areas where excessive noise is undesirable, such as hospitals or nursing homes, so the machine needs to be as quiet as possible in operation. The vacuum system creates most of the noise generated by automatic floor scrubbers. Current means of reducing the sound level is to attach a porous, open-cell acoustical foam tube onto the outlet port of the vacuum system. However, since the automatic floor scrubbers are designed to be as compact as possible, the length of the tube could not be any substantial length, resulting in a compromise in sound level reduction.
Thus, a need exists for improved methods of providing dampening of the vibrations caused by floor-care equipment moving over rough surfaces. Additionally, a need exists for improved methods of reducing the sound level generated by the vacuum system of floor-care equipment.